U.S. patent application number 12/103780 was filed with the patent office on 2008-10-30 for magnet system for an electrical actuator.
Invention is credited to Rudolf Mikl.
Application Number | 20080266039 12/103780 |
Document ID | / |
Family ID | 39683478 |
Filed Date | 2008-10-30 |
United States Patent
Application |
20080266039 |
Kind Code |
A1 |
Mikl; Rudolf |
October 30, 2008 |
Magnet System for an Electrical Actuator
Abstract
A magnet system for an electrical actuator includes a
substantially U-shaped magnet yoke having substantially parallel
first and second pole legs connected by a yoke web. The first pole
leg has a longitudinal end section bent out of a plane of the first
pole leg. A longitudinal side of the longitudinal end section forms
a first magnet pole. The second pole leg has an end face forming a
second magnet pole.
Inventors: |
Mikl; Rudolf; (Arbesthal,
AT) |
Correspondence
Address: |
BARLEY SNYDER, LLC
1000 WESTLAKES DRIVE, SUITE 275
BERWYN
PA
19312
US
|
Family ID: |
39683478 |
Appl. No.: |
12/103780 |
Filed: |
April 16, 2008 |
Current U.S.
Class: |
335/282 |
Current CPC
Class: |
H01H 50/163 20130101;
H01H 50/24 20130101; H01H 50/36 20130101; H01H 50/641 20130101 |
Class at
Publication: |
335/282 |
International
Class: |
H01F 3/00 20060101
H01F003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 24, 2007 |
DE |
102007019684.0 |
Claims
1. A magnet system for an electrical actuator, comprising: a
substantially U-shaped magnet yoke having substantially parallel
first and second pole legs connected by a yoke web; the first pole
leg having a longitudinal end section bent out of a plane of the
first pole leg, a longitudinal side of the longitudinal end section
forming a first magnet pole; and the second pole leg having an end
face forming a second magnet pole.
2. The magnet system of claim 1, wherein the longitudinal end
section extends substantially perpendicular to the first pole
leg.
3. The magnet system of claim 1, further comprising an armature
that pivots between an open position and a closed position, the
armature contacting at least the first magnet pole in the closed
position.
4. The magnet system of claim 1, wherein the first pole leg is a
yoke leg and the second pole leg is a core leg, the core leg being
provided with a coil body.
5. The magnet system of claim 1, wherein the first and second
magnet poles are in the same plane.
6. The magnet system of claim 1, wherein the first magnet pole has
a larger contact area than the second magnet pole.
7. The magnet system of claim 1, wherein the second pole leg and
the yoke web have the same cross-sectional area.
8. The magnet system of claim 1, wherein the longitudinal end
section extends toward the second pole leg.
9. The magnet system of claim 1, wherein the longitudinal end
section extends away from the second pole leg.
10. The magnet system of claim 1, wherein the first pole leg has a
widened region extending from a substantially center region of the
first pole leg through the longitudinal end section.
11. The magnet system of claim 10, wherein the widened region has a
recess adjacent the longitudinal end section.
12. Magnet system for an electrical actuator, comprising: a
substantially U-shaped magnet yoke having a core leg extending
substantially parallel to a yoke leg, the core leg and the yoke leg
being connected by a yoke web; the yoke leg having a longitudinal
end section bent out of a plane of the yoke leg and extending
substantially perpendicular thereto, the yoke leg having a widened
region extending from a substantially center region of the yoke leg
through the longitudinal end section, a longitudinal side of the
longitudinal end section forming a yoke pole; and the core leg
being provided with a coil body, the core leg having an end face
forming a second magnet pole.
13. The magnet system of claim 12, further comprising an armature
that pivots between an open position and a closed position, the
armature contacting at least the yoke pole in the closed
position.
14. The magnet system of claim 12, wherein the yoke pole and the
core pole are in the same plane.
15. The magnet system of claim 12, wherein the yoke pole has a
larger contact area than the core pole.
16. The magnet system of claim 12, wherein the core leg and the
yoke web have the same cross-sectional area.
17. The magnet system of claim 12, wherein the widened region has a
recess adjacent the longitudinal end section.
18. The magnet system of claim 12, wherein the longitudinal end
section extends toward the core leg.
19. The magnet system of claim 12, wherein the longitudinal end
section extends away from the core leg.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date under
35 U.S.C. .sctn.119(a)-(d) of German Patent Application No. 10 2007
019 684.0, filed Apr. 24, 2007.
FIELD OF THE INVENTION
[0002] The invention relates to a magnet system for an electrical
actuator comprising a substantially U-shaped magnet yoke having
substantially parallel first and second pole legs connected by a
yoke web.
BACKGROUND
[0003] Magnet systems for electrical actuators have broad
industrial applicability in domestic, entertainment, motor vehicle,
and industry sectors and are required, for example, in print
relays, mains relays, miniature switching relays and miniature
power relays. In the motor vehicle sector, so-called monostable or
bistable relays are also required. These include, for example,
bistable latching relays, which without further energy conversion
remain continuously in a closed or open state, in order to reduce
power conversion of a motor vehicle. Monostable relays, such as,
for example, for an indicating device of the motor vehicle, return
to their original open or closed state following excitation of a
coil body.
[0004] Because of their mass use, the above-described electrical
actuators need to be manufactured as cheaply as possible. The best
way to reduce the cost of a mass produced electrical actuator is to
minimize the material consumption of a magnet system in the
electrical actuator. This relates in particular to the coil body,
which comprises an excitation winding consisting mostly of precious
metals, such as copper and silver. Furthermore, this relates to the
magnet yoke, which should preferably likewise be able to be
manufactured with a low material consumption. Moreover, it is
advantageous particularly in cramped conditions if such an
electrical actuator has a minimal space requirement.
SUMMARY
[0005] It is therefore an object of the invention to provide a
magnet system for an electrical actuator which has a low unit price
and small dimensions.
[0006] This and other objects are achieved by a magnet system for
an electrical actuator comprising a substantially U-shaped magnet
yoke having substantially parallel first and second pole legs
connected by a yoke web. The first pole leg has a longitudinal end
section bent out of a plane of the first pole leg. A longitudinal
side of the longitudinal end section forms a first magnet pole. The
second pole leg has an end face forming a second magnet pole.
[0007] This and other objects are further achieved by a magnet
system for an electrical actuator comprising a substantially
U-shaped magnet yoke having a core leg extending substantially
parallel to a yoke leg. The core leg and the yoke leg are connected
by a yoke web. The yoke leg has a longitudinal end section bent out
of a plane of the yoke leg that extends substantially perpendicular
thereto. The yoke leg has a widened region extending from a
substantially center region of the yoke leg through the
longitudinal end section. A longitudinal side of the longitudinal
end section forms a yoke pole. The core leg is provided with a coil
body. The core leg has an end face forming a second magnet
pole.
DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a magnet system according to
the prior art;
[0009] FIG. 2 is a perspective view of the magnet system from FIG.
1 showing a coil body arranged on a core leg;
[0010] FIG. 3 is a perspective view of an electrical actuator
according to the prior art with the magnet system from FIG. 2;
[0011] FIG. 4 is a perspective view of a magnet system according to
a first embodiment of the invention;
[0012] FIG. 5 is a perspective view of the magnet system from FIG.
4 showing the coil body arranged on the core leg;
[0013] FIG. 6 is a perspective view of an electrical actuator with
the magnet system from FIG. 4;
[0014] FIG. 7 is a perspective view of a magnet system according to
a second embodiment of the invention;
[0015] FIG. 8 is a perspective view of the magnet system from FIG.
7 showing the coil body arranged on the core leg;
[0016] FIG. 9 is a perspective view of an electrical actuator with
the magnet system from FIG. 7; and
[0017] FIG. 10 is a diagram comparing a magnet curve of the magnet
system according to the prior art and a magnet curve of a
comparable magnet system according to the invention.
DETAILED DESCRIPTION OF THE EMBODIMENT(S)
[0018] FIGS. 1-3 show a magnet system 10 for an electrical actuator
1 according to the prior art. The electrical actuator 1 may be, for
example, a power relay or a mains relay. As shown in FIG. 1, the
magnet system 10 has a substantially U-shaped magnet yoke 100. The
magnet yoke 100 includes first and second pole legs consisting of a
yoke leg 110 and a core leg 120, respectively. The core leg 120 and
the yoke leg 110 are integrally connected by a yoke web 130. The
yoke leg 110 extends substantially parallel to the core leg 120,
and the yoke web 130 extends there between and substantially
perpendicularly thereto. The yoke web 130 has substantially the
same cross-sectional area A as the core leg 120. The magnet yoke
has first and second magnet poles consisting of a yoke pole 111 and
a core pole 121, respectively. An end face of the core leg 120
forms the core pole 121, and an end face of the yoke leg 110 forms
the yoke pole 111. The core pole 121 and the yoke pole 110 lie
substantially in the same plane. To conduct a magnetic flux better
in an area of the yoke pole 111, the yoke leg 110 has a widened
region 112 at an end thereof. As shown in FIG. 2, a coil body 14 is
disposed about the core leg 120.
[0019] An elongated, plate-shaped, and substantially flat hinged
armature 200 is provided at a free end of the core leg 120. The
armature 200 is supported by an armature spring (not shown) and
pivots between an open position shown in FIG. 3 and a closed
position shown in FIGS. 1-2 depending on the excitation of the coil
body 14. In the open position, at least one portion of the armature
200 abuts the core pole 121 of the core leg 120. In the closed
position, the armature 200 abuts the core pole 121 and the yoke
pole 111. The mechanical contact surfaces of the armature 200 may
be located, for example, longitudinal end sections thereof.
[0020] For example, starting with the armature 200 in the open
position, when a corresponding flow of current goes through the
coil body 14, the folded-back armature 200 moves, due to the spring
force of the armature spring (not shown), towards the yoke pole 111
and contacts the yoke pole 111 on a front face thereof. An
analogous occurrence takes place with the core pole 121. In the
closed position, the magnetic circuit is closed via the yoke pole
111 of the yoke leg 110 and the core pole 121 of the core leg 120,
which circuit opens again when the current is removed from the coil
body 14.
[0021] As shown in FIG. 3, the magnet system 10 is arranged in an
insulating housing 20. The coil body 14 is supplied with a current
via electrical connections 15 extending into the housing 20. The
armature 200 is connected to a slide 30, which is coupled to the
armature 200 at a side 12. On a side opposite the armature 200, the
slide 30 is connected to moveable spring contacts (not shown)
arranged in a receptacle 22 on the housing 20. The slide 30 can
move the moveable spring contacts 30 into contact with fixed spring
contacts (not shown) also arranged in the receptacle 22, as a
result of movement of the armature 200.
[0022] In the electrical actuator 1 shown in FIGS. 1-3, the
electrical actuator 1 and/or the magnet system 10 has a fixed
external dimension dependent upon the winding height of the coil
body 14 or the predetermined number of windings in the coil body
14, and the yoke pole 111 has a surface area dependent upon the
characteristics of the coil body 14. Thus, it is difficult to alter
the characteristics of the electrical actuator 1 and/or the magnet
system 10, because lowering the winding height of the coil body 14
or reducing the number of windings in the coil body 14 results in a
smaller magnetic flux with the same electrical activation of the
coil body 14.
[0023] FIGS. 4-6 show the electrical actuator 1 configured with a
magnet system 10 according to a first embodiment of the invention.
In the magnet system 10 according to the first embodiment of the
invention, the winding height of the coil body 14 and/or the number
of windings in the coil body 14 has been reduced and the surface
area of the yoke pole 111 has been enlarged while overcoming the
disadvantages of the prior art.
[0024] As shown in FIGS. 4-5, the surface area of the yoke pole 111
is enlarged by providing a bend in the yoke leg 110 at a free
longitudinal end section 119 of the yoke leg 110 adjacent the
armature 200. The longitudinal end section 119 is bent out of the
plane of the yoke leg 110 and substantially perpendicular thereto.
In the illustrated embodiment, the longitudinal end section 119 is
bent away from the core leg 120 and substantially perpendicular
thereto. The surface area of the yoke pole 111 may be varied by
varying the length of the bent longitudinal end section 119.
[0025] To better conduct the magnetic flux in the area of the yoke
pole 111, the widened region 112 of the yoke leg 110 extends from a
substantially central region of the yoke leg 110 through the
longitudinal end section 119. To facilitate the bending of the
longitudinal end section 119, a portion of the widened region 112
adjacent the longitudinal end section 119 is provided with a recess
113 on a side of the yoke leg 110 facing away from the core leg
120. The recess 113 allows the bending of the longitudinal end
section 119 to be made easier and makes sure no material
disruptions occur in the area of the bending.
[0026] As a result of the bend, the yoke pole 111 of the yoke leg
110 is no longer formed from the end face of the yoke leg 110, but
is formed from a section of a longitudinal side 118 of the yoke leg
110. In the illustrated embodiment, the longitudinal side 118 is
the side of the yoke leg 110 opposite from the side of the yoke leg
110 having the recess 113. In other words, the longitudinal side
118 is the side of the yoke leg 110 which is or was facing the core
leg 120. Thus, the longitudinal side 118 of the longitudinal end
section 119 is mechanically contactable by the armature 200 when
the armature 200 is in the closed position.
[0027] In order to facilitate contact by the armature 200, the core
pole 121 and the yoke pole 111 lie in substantially the same plane.
In the illustrated embodiment, this plane extends substantially
perpendicular to a longitudinal extension of the core leg 120 and
the yoke leg 110 and substantially parallel to a transverse
extension of the of the core leg 120 and the yoke leg 110. For this
purpose, the longitudinal end section 119 of the yoke leg 110 is
bent correspondingly and the core pole 121 of the core leg 120 is
arranged correspondingly beveled relative to a remainder of the
core leg 120. It will be appreciated by those skilled in the art,
however, that the yoke pole 111 and the core pole 121 need not lie
in substantially the same plane and could alternatively be offset
in a direction of the core leg 120 and the yoke leg 110 or the core
pole 121 and/or the yoke pole 111 could be arranged at an angle
relative to the core leg 120 and the yoke leg 110. The armature 200
would then need to be configured to compensate for the
aforementioned deviations.
[0028] In the magnet system 10 shown in FIGS. 4-6, the height of
the yoke web 130 is reduced and therefore the distance between the
pole leg 110 and the core leg 120 is reduced due to the reduction
in the winding height of the coil body 14. The longitudinal end
section 119 of the yoke leg 110 then utilizes the space freed by
the reduction in the winding height of the coil body 14. As a
result, the height of the coil body is reduced over the prior art,
but the electrical actuator 1 has the same dimensions as a result
of the addition of the longitudinal end section 119 and the
increase in the height of a contact side 211 of the armature 200.
Additionally, a free space (not shown) may be provided between the
armature 200, the core leg 120, the coil body 14, and the yoke leg
110 on which the bend for the longitudinal end section 119 is
provided.
[0029] FIG. 6 shows the magnet system 10 arranged in the housing
20. Due to the shape of the magnet system 10, more space is
available in the region outside the yoke leg 110 and on the right
(with reference to FIG. 6) next to the yoke pole 111 for the slide
30, which is coupled to the armature 200. Due to the available
space, the danger of the slide 30 touching a cover (not shown) of
the electrical actuator 1 and thus being able to be blocked is
minimized. Moreover, because the housing 20 and the cover (not
shown) are made from a plastic material, the housing 20 and the
cover can be configured more simply according to the invention.
[0030] FIGS. 7-9 show the electrical actuator 1 configured with a
magnet system 10 according to a second embodiment of the invention.
In the magnet system 10 according to the second embodiment of the
invention, the longitudinal end section 119 of the yoke leg 110 is
bent towards the core leg 120. The longitudinal end section 119 is
configured such that the longitudinal end section 1119 does not
overlap the coil body 14 and therefore does not cause any magnetic
interference fields in the yoke pole 111. The longitudinal side 118
of the yoke leg 110 facing away from the core leg 120 now forms the
yoke pole 111. To facilitate the bending of the longitudinal end
section 119, a portion of the widened region 112 adjacent the
longitudinal end section 119 is provided with a recess 113 on a
side of the yoke leg 110 facing towards the core leg 120. In other
words, the recess 113 is formed on the side of the yoke leg 110
opposite from the longitudinal side 118 of the yoke leg 110 which
forms the yoke pole 111.
[0031] As shown in FIG. 8, a free space 17 is formed in the magnet
system 10 between the coil body 14 and the yoke leg 110, as a
result of the increase in the height of the yoke web 130 to
accommodate the longitudinal end section 119. Due to the free space
17 between the coil body 14 and the yoke leg 110, space is created
for further devices of the electrical actuator 1, as shown FIG. 9.
Furthermore, a free space 16 is provided between the armature 200,
the core leg 120, the coil body 14, and the yoke leg 110. Because
the magnet system 10 according to the second embodiment of the
invention has similar dimensions to the magnet system 10 of the
prior art, the magnet system 10 can more easily be worked into an
existing assembly system.
[0032] FIG. 10 shows a comparison of a magnet curve I produced by
the electrical actuator 1 of the prior art and a magnet curve II
produced by the electrical actuator 1 of the invention. The
abscissa of the diagram is an average distance s between the
armature 200 and the yoke pole 111 and the ordinate of the diagram
is a magnetic force F between the armature 200 and the yoke pole
111.
[0033] Magnet curve I represents the magnet system 10 of the prior
art with the cross-sectional area A of the core leg 120 of
approximately 4.0-4.5 mm.times.2.5 mm. The magnet curve II
represents the magnet system 10 according to the invention with the
winding height of the coil in the coil body 14 being reduced by
approximately 35-45%, preferably by approximately 40%, and the area
of the yoke pole 111 is increased by approximately 45-65%,
preferably by approximately 50-60%. The cross-sectional area A of
the core leg 120 is approximately 4.5-5.0 mm.times.2.0 mm. In this
case a material thickness of the magnet yoke 100, in particular a
material thickness of the core leg 120, can be reduced by
approximately 10-25%, in particular by approximately 12.5-20% and
preferably by approximately 15%.
[0034] It is easily recognizable that the magnet system 10
according to the invention with the enlarged end surface of the
yoke pole 111 and smaller coil body 14 is considerably stronger in
the relevant open state of the magnet system 10 than the magnet
system 10 according to the prior art. Due to the reduction in the
winding height of the coil body 14, a substantial amount of the
coil, which consists mostly of copper or silver, can be saved. Due
to this, the magnet system 10 with the coil body 14 does not become
weaker due to the minimized use of expensive metals, but even
somewhat stronger in the relevant open state of the electrical
actuator 1. The reason for this is the markedly greater area of the
yoke pole 111, which at least compensates for the disadvantage of
the reduced winding height.
[0035] Thus compared with the prior art, which has a
cross-sectional area A of the magnet yoke 100 in the region of the
coil body 14 of 4.0-4.5 mm.times.2.5 mm, a quantity of copper that
is approximately 40-50% smaller results in the case of the
cross-section of the magnet yoke 100 of the invention in the
cross-sectional area A of the coil body 14 of 4.0-5.0 mm.times.2.0
mm and an enlargement of the end surface of the yoke pole 111 by
50-60%. Thus, the cross-sectional area A of the magnet yoke 100 in
the region of the coil body 14 and preferably also in a region of
the yoke web 130 is approximately 4-13 mm.sup.2, preferably
approximately 5-12.5 mm.sup.2, more preferably approximately
7.5-11.5 mm.sup.2, in particular approximately 8.5-10.5 mm.sup.2
and in particular preferably approximately 9-10 mm.sup.2. In the
electrical actuator 1 according to the invention, the yoke pole 111
is approximately 40-80 mm.sup.2, preferably approximately 45-70
mm.sup.2, more preferably approximately 50-65 mm.sup.2, in
particular approximately 55-62.5 mm.sup.2 and in particular
preferably approximately 57.5-60 mm.sup.2 and/or a mass for the
coil body 14 is approximately 1.0-3.5 g, 1.25-3.25 g, preferably
approximately 1.5-3 g, in particular approximately 1.7-2.5 g, in
particular preferably approximately 1.8-2.25 g and in particular
especially preferably approximately 1.9-2.1 g. Thus, for the magnet
system 10 according to the invention, for example, a minimization
of the copper requirement for the coil body 14 from 3.5 g in the
prior art to 1.9 g thus results. A contact overlap of the contact
side 211 of the armature 200, relative to its overall lateral area
between the yoke pole 111 and the core pole 121 is approximately
30-70%, preferably approximately 35-60%, in particular
approximately 40-55% and in particular preferably approximately
45-50% with the yoke pole 111.
[0036] As a result, it is possible according to the invention to
significantly increase the magnetic force F between the armature
200 and the yoke pole 111 when current is flowing to the coil body
14, by reducing the winding height of the coil body 14 and
increasing the area of the yoke pole 111.
[0037] Due to the fundamental idea of the invention wherein
reduction of an exciter mass of the coil body 14 and compensation
or overcompensation for this assumed disadvantage by enlargement
the yoke pole 111, not only is this invention applicable to magnet
systems for the relays 1, but the invention is applicable to all
magnet systems for electrical actuators such as, for example,
monostable or bistable electrical actuators. This relates to, for
example, miniature print relays, mains relays, power relays, card
relays, safety relays, industrial relays, multimode relays etc.
[0038] The foregoing illustrates some of the possibilities for
practicing the invention. Many other embodiments are possible
within the scope and spirit of the invention. For example, the
arrangement of the components of the invention is magnetically or
kinematically reversible. It is thus possible, for example, to
exchange the yoke leg 110 and the core leg 120. Furthermore, it is
conceivable to provide or couple an armature 200 not on the core
leg 120 but on the yoke leg 110. It is also possible also to
provide the coil body 14 on the yoke leg 110. These variants may be
realized individually or in combination in all embodiments of the
invention. It is, therefore, intended that the foregoing
description be regarded as illustrative rather than limiting, and
that the scope of the invention is given by the appended claims
together with their full range of equivalents.
* * * * *